Summary The Dominantly Inherited Alzheimer Network-Trials Unit (DIAN-TU) was formed in 2011 to direct the design and management of interventional therapeutic trials of individuals with and at risk of Autosomal dominant Alzheimer?s disease (ADAD), a rare form of Alzheimer?s disease caused by mutations. Findings from ADAD indicate a cascade of Alzheimer biomarker changes that begin at least 20 years before symptomatic onset of disease which align with findings in the more common, late-onset sporadic AD (SAD). Because of the similarities with SAD, it is essential that data and findings from clinical trials in the ADAD population be disseminated and shared as quickly as possible to advance the field of AD research. The DIAN-TU developed and launched its ADAD prevention trial platform (DIAN-TU-001, NCT01760005) in 2012 as an international phase II/III randomized, placebo-controlled, biomarker study of potential disease modifying therapies in individuals with and at risk for ADAD. This trial was the first prevention and treatment trial in ADAD, and the first prevention trial using anti-amyloid therapies. Since the launch, the DIAN-TU-001 trial transitioned to a 4 year cognitive endpoint trial, incorporated an ADAD-specific cognitive composite and disease progression statistical model, and adapted to add new drug and cognitive run-in arms. The DIAN-TU-001 trial collects extensive imaging, biofluid, clinical, and cognitive data at baseline and annual visits (over 5000 variables per participant per visit). This broad and all-inclusive dataset will allow for comprehensive analyses of disease biomarkers, disease progression, and impact of therapies on all aspects of AD, thus sharing of this data as quickly as possible is critical. The DIAN-TU trial is a public/private partnership with funding from the NIH, pharma, and philanthropic sources. A NIH funded clinical trial in ADAD allows for publicly accessible data sets and biomarker banks to inform if symptomatic AD dementia can be prevented or delayed in ADAD subjects, and the changes in biomarkers which may track the effectiveness of AD prevention. The DIAN-TU is committed to the sharing of research resources with minimum restriction. However, it is most important that data sharing not impact the integrity of the trial and threaten regulatory approval of a treatment for AD. Also, because of our special population, special care has to be taken to ensure even blinded data doesn?t reveal or give a perception of a participant?s mutation status. This administrative supplement will support the resources to develop and implement processes and procedures for DIAN-TU trial data and sample sharing that will allow for easier access to trial data while maintaining the integrity of the trial and confidentiality of participants. Sharing of this ADAD trial data is critical to advance the search for surrogate biomarkers and for a pathway to preventing AD in the general population.